I have never liked that word talking about the real God..
For the real God is only mystical to those that DON'T know him.. or only know of him.. God is quite real to those that do.. I know its a sidebar but that word defames God in my experience.. A common word and expression but it chafes my hindquarters ever time.. On the other hand ALL ancient and modern gods(religions) were mystical.. thats why they were called Mystery Religions.. Reality is not a mystery.. There I said it, I'm done..
Indeed, the word "mysticism" - like the word "myth" - has managed to pick up some unpleasant intension - probably because both words are often used to describe malevolent or bizarre occults.
But of a truth, the word "mysticism" merely means divine knowledge, or more specifically, direct Spiritual knowledge - thus in Christian theology, the indwelling Spirit is called Christian mysticism. We have the mind of Christ.
Likewise a "myth" is secret speech, a lesson or teaching in story form. By using allegories, metaphors and other literary devices myths convey understanding where more direct language fails. Parables are like short myths. The "lesson" conveyed by a myth may be insignificant or profound.